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Researchers Develop New Process for Direct Conversion of Cellulose into Furanics

Researchers at the University of California, Davis have developed a new method for the direct conversion of cellulose into furanics, which can become the basis for new biofuels. The simple, low-cost process delivers furanic compounds in yields not yet achieved, according to Mark Mascal and Edward B. Nikitin in an early view paper published online 1 August in the journal Angewandte Chemie.

Currently, biofuel producers primarily use starch, which is broken down to form sugars that are then fermented to give ethanol. Cellulose, however, is the most common form of photosynthetically fixed carbon. Exploiting that resource for fuels via a fermentation pathway—e.g., cellulosic ethanol—is difficult because the degradation of cellulose into its individual sugar components, which could then be fermented, is a slow and expensive process.

Another problem is that the carbon economy of glucose fermentation is poor. For every 10 g of ethanol produced, you also release 9.6 g CO2.

—Mark Mascal

Researchers are thus looking for effective approaches to biomass conversion which avoid fermentation altogether and exploit all of the available carbon present. One of the promising areas of effort in this area is the production and use of furanics—high-energy, furan-based organic liquids. Work at the University of Wisconsin led by Professor James Dumesic (earlier post) showed that fructose could be efficiently converted, via 5-hydroxymethyfurfural (HMF). Researchers at the Pacific Northwest National Laboratory (PNNL) led by Z. Conrad Zhang (earlier post) have converted glucose directly and with high yield to HMF.

Mascal and Nikitin developed a process for the conversion of cellulose directly—i.e., without relying on glucose or fructose—into furanic products in isolated yields of greater than 80% by conversion mainly into 5-(chloromethyl)furfural (CMF), a hydrophobic molecule.

The process entailed adding microcrystalline cellulose to a stirred solution of lithium chloride (5 wt%) in concentrated hydrochloric acid to give a homogeneous mixture, which was introduced into a reaction chamber containing 1,2-dichloroethane. The solvent was heated to reflux and the aqueous slurry was kept at 65°C with continuous mechanical stirring and extracted for 18 h. At this point, a further solution of LiCl in concentrated hydrochloric acid was added to the reaction chamber and extraction continued for another 12 h. The combined organic extracts were distilled to recover the solvent.

The process yielded 71% CMF; 8% 2-(2-hydroxyacetyl)furan; 5% HMF; and 1% levulinic acid. Total, isolated yield of these four simple organics was thus 85%. Applied to glucose, the process delivered the same organics in yields of 71%, 7%, 8% and 3%, respectively. Applied to sucrose, it yielded 76%, 6%, 4% and 5% respectively.

While CMF itself is not a biofuel candidate, it can be combined with ethanol to give ethoxymethylfufural (EMF). CMF can also be catalytically hydrogenated to yield 5-methylfurfural (HMF). Both of these compounds are suitable as fuels. EMF has previously been investigated and found to be of interest in mixtures with diesel by Avantium Technologies, a spin-off of Shell. (Earlier post.)

While future reports will address further optimization, scaleup, and applications of the method to raw biomass, these preliminary results suggest that this simple, efficient approach to cellulose deconstruction has the potential, at the very least, to complement fermentation as a means to produce biomass-derived automotive fuels, and to establish furanics both as a renewable energy source and industrial chemical feedstock of the future.

—Mascal and Nikitin (2008)

Resources

  • Mark Mascal and Edward B. Nikitin (2008) Direct, High-Yield Conversion of Cellulose into Biofuel. Angew. Chem. Int. Ed. 2008, 47, 1 – 4 doi: 10.1002/anie.200801594

Comments

HarveyD

Another way to convert cellulosic feedstock to liquid fuel is good news (for many).

However, even with a 100% feedstock to fuel conversion efficiency + an excellent 2% sun to feedstock efficiency + a high 20% fuel to wheel ICE machine efficiency; the total sun to wheel efficiency would barely reach 0.2%

High efficiency, 20% PV + ESSU + electric motors could give about (20% x 80%) = 16% total sun to wheel efficiency or over 80 times that of any cellulosic fuel approach.

Why not prioritize the development and use of the second approach. It has much more potential and is much more environment friendly. Many people could eventually produce (most of) their own e-energy with rooftop solar panels and fixed home ESSU.

Quick charge on-board ESSUs and ESSU exhange stations will eventually supply all the e-range required.

We should be planning ICE machines progressive phase out now.

Aussie

Some questions; is the energy return (EROEI) better than the 1.25 claimed for conventional ethanol? I see the energy sapping distillation step is still needed. Can the process be made continuous? 30 hour batches seems cumbersome. Can the products blend easily (say 50/50) with conventional petrol and diesel?

JC

Right Harvey - isn't it amazing that the media hasn't gone into apoplexy about the lack of PV development and mass installation. The answer is staring us in the face, and all we hear about is drilling for oil.

JMartin

The media is just that -- media, not news. They braodcast what they are fed, which is political one-liners, not facts, news, or information. Since most politicians don't know anything about this stuff, they fight over whatever headline grabs the uninformed voter.

One thing Bush has been good at is grabbing credit for whatever technology did make the headlines (after the fact of cours): hydrogen economy, switchgrass, even the Mars lander he wanted credit for.

Paul F. Dietz

I'd be concerned the process makes chlorinated organic compounds. Are the aromatics in lignin also getting chlorinated? Is any dioxin going to be produced?

Henry Gibson

At last an industrial chemical process to do what should not be done except on materials othewise destined for landfills. All other cellulostic materials should be delivered to enrich the soil so that people can eat.

A direct, efficient process for making natural gas into liquid methanol is a major goal of industrial chemistry. Menthanol is a good enough fuel for all ground transportation needs. The low energy density makes commercial aircraft operation more expensive and difficult than with jet fuel, but still possible for short range.

Nuclear reactors with chemical plants to produce liquid fuels from CO2 and water are the ultimate cheapest answer to the fuel problem. The sun, with nuclear energy, produced liquid and solid fuels in an inefficient way and we have used much of them. Now nuclear energy can do it in a far more efficient way and recycle green-house gases faster than nature does.

Electricity will be used for plug-in-hybrids, but planes need liquid (or solid pure carbon powder) fuels.

..HG..

Engineer-Poet

I'm impressed by the relatively reasonable conditions here.  65°C is easily produced by flat-plate solar collectors or waste heat from other processes.  But where do you get dichloroethane?  How much energy is involved in regenerating the HCl?  Is any byproduct suitable for producing hydrogen, or would that have to come from a separate pathway?

There's so much between lab chemistry and industrial processes....

sjc

"..extracted for 18 h....
continued for another 12 h..."

The long dwell times make for a big pipeline if you want significant quantities in a continuous process.

Gasification is a quick process pipeline that has flexible inputs and versatile outputs.

Engineer-Poet

True, but gasification also has substantial process losses.

Henric

@Engineer-Poet

The efficiency of a gasification process can be about 80 %, i.e., 80 % of biomass thermal energy is converted in the thermal energy of the synthesis gas. Synthesis gas to liquids is about 50 % efficient. The overall thermal efficiency is about 30 to 50 %. That's quite high, and no additional inputs of any chemicals are needed.

sjc

Considering oil to gasoline is about 80% efficient on a BTU basis, gasification of biomass to synthesis gas is not bad. It depends on what you make with the synthesis gas.

Methane, methanol, ethanol all have different efficiencies on a BTU basis. As I have stated, I favor gasification of biomass to methane, which I believe is the most efficient of the three.

If gasification were the answer, we wouldn't need forums like this. Pyrolysis and gasification both definitely have cost effectiveness issues. This method appears to beat out fermentative ethanol on every count. It will need some process optimization for sure, but let's think about it - a cheap, nontoxic, nonvolatile, nonhydrophilic fuel made using nothing more sophisticated than HCl... doesn't sound bad.

jcwinnie

@ previous anonymous commentor

It particularly sounds good if you lack any knowledge of MSDS.

http://en.wikipedia.org/wiki/1,2-Dichloroethane_(data_page)

@ Harvey D.

Let me guess that you are other than an employee of Shell ;>

sjc

"If gasification were the answer, we wouldn't need forums like this..."

We don't need forums like this. This forum does nothing. We do not set energy policy nor form huge capital investment. I fail to see the logic in that statement.

Henric

@sjc

Yes, syngas to methane is very simple. Take it and pass it over Ni catalyst at 300 deg C, and there you have it. The problem is that it is a huge pain to use methane as a transportation fuel. If it was not, why then it is used on limited scale only? I now of only some places where it is used.
We need liquid fuels that are easily stored and distributed. Syngas to liquids is not hard at all.

sjc

I have read that there are millions of NG vehicles in the world but only 150,000 of them in the U.S. and most of those are not personal automobiles.

There are duel fueled vehicles that run on NG or gasoline. I think that the main objection is the large tank and short range. ANG may be able to solve both problems.

What I meant was that if gasification was the answer, we wouldn't even be discussing this work. The matter would be settled. We'd be setting up massive biogasification plants all over the country, and ethanol's number would be up.

Good guess, I am other than an employee of Shell. And, I do not lose sleep over the use of halogenated hydrocarbons, particularly if they are recycled (which is the case in this work - read the paper).

Engineer-Poet

Quoth Henric:

The efficiency of a gasification process can be about 80 %, i.e., 80 % of biomass thermal energy is converted in the thermal energy of the synthesis gas. Synthesis gas to liquids is about 50 % efficient. The overall thermal efficiency is about 30 to 50 %. That's quite high...
So you've got 40% field-to-tank.  Multiply by 14.9% tank-to-wheels, you get a net efficiency of roughly 6%.  That sucks, big time.  Old-fashioned steam locomotives were about that good.

If we can get rid of the gasification and synthesis processes with a chemical reaction going on at less than the boiling point of water, so much the better.  However, the gains from this will be nothing compared to what we'll get from electrification.

Henric

@Engineer-Poet

Electrification can not be done - there will never be a good storage unit. Except maybe for superconducting coil type of storage if a room temp superconductor ever gets discovered. But that's some time in the future.

I think gasification of biomass to liquids is a good interim solution for many places where there is a lot of forests. Remember that many cars run on wood gas from chips at some point i.e. gasogenes. So BtL would basically be like the chips are converted to liquid in plant on large scale so people would not have to have the gasogene on their cars.

Engineer-Poet
Electrification can not be done - there will never be a good storage unit.
Where I come from, sufficiently good storage units already exist.  Did I get off at the Bizarro World exit by mistake?

Lots of electrification requires no storage at all, e.g. electrified rail to replace diesel trains and diesel trucks.  Today's batteries are sufficient to give 120 miles range in a sufficiently aerodynamic vehicle for under $30000 (Aptera).  You only run into "cannot" if you demand petroleum-vehicle equivalence in all or most categories from a pure EV.  This is not a problem for PHEV.

You know your argument is a failure when GM is bringing your "impossibility" to market in about 2 years.

Henric

Engineer, so you are of the opinion that Li-ion batteries are an adequate storage unit for transportation purposes.
I don't think so. They are very expensive to make, have you thought about how much CO2 is emitted when one such battery is made in the factory? They have short lifecycle, considerable loses on charging/discharging. where are you going to dump old batteries? Recycling is expensive and emit CO2? The whole infrastructure of the battery manufacturing/charging/disposing of and recycling is a huge mess in my opinion. And not very efficient.
Liquid hydrocarbon fuels have huge advantages. ICE is simple and efficient. BtL fuels are easy to make. No emissions, simple infrastructure. Wood is collected by hand, and hauled to the BtL plant with a horse-drawn carriage. No emmisios, simple and clean. What do you think?

Engineer-Poet
Engineer, so you are of the opinion that Li-ion batteries are an adequate storage unit for transportation purposes.
More than adequate for certain types of vehicles.  The major hybrid manufacturers are switching from NiMH to newer-chemistry Li-ion.  Even lead-acid is adequate if it's used in a technology like Firefly Energy's carbon-substrate electrodes.
They are very expensive to make
Much of this expense is due to manufacturing technology, not the raw materials.  That cost can be brought down.
have you thought about how much CO2 is emitted when one such battery is made in the factory?
Have you?

A gallon of gasoline contains about 33.7 kWh of energy; at 20% conversion efficiency, it will put 6.7 kWh to the wheels.  It will produce about 19 pounds of CO2 upon combustion.  A kilogram of Li-ion batteries will hold on the order of 100 Wh, so it takes about 67 cycles at 100% DoD to put the same amount of energy to the wheels.  The lifetime of a modern non-cobalt Li-ion cell can be upwards of 2000 cycles, replacing about 30 gallons of gasoline.  If this kilogram of Li-ion battery takes 500 grams of carbon to make, it will put about 4 pounds of CO2 into the atmosphere.  This makes it about 1/150 as carbon-intensive as liquid fuel.

They have short lifecycle, considerable loses on charging/discharging.
Li-ion is upwards of 95% efficient.
where are you going to dump old batteries?
Batteries are the most completely recycled consumer good in the USA.  Vehicle traction batteries would be almost 100% recycled if they received a rebate of a core charge.
Recycling is expensive and emit CO2?
If recycling takes less energy than making a battery from virgin ores, is this a problem?
The whole infrastructure of the battery manufacturing/charging/disposing of and recycling is a huge mess in my opinion. And not very efficient.
150 times as good as liquid fuels, of which you seem to have a high opinion.  There seems to be something wrong with your thinking processes.
Liquid hydrocarbon fuels have huge advantages. ICE is simple and efficient.
There's an example of what's wrong.  ICE is not efficient, and neither simple nor cheap if you want it to be clean.
BtL fuels are easy to make. No emissions, simple infrastructure. Wood is collected by hand, and hauled to the BtL plant with a horse-drawn carriage. No emmisios, simple and clean. What do you think?
I think you're wrong on every point.
  1. BTL fuels are expensive, more expensive than petroleum even at today's prices.
  2. If the infrastructure was simple, we'd have a lot of it.  Instead, we have mostly laboratory-scale plants for petroleum-compatible liquid fuels or processes like rapid pyrolysis which yield highly acid, low-energy-density bio-oil.
  3. If you think the implied amount of horse crap is "clean", you're dreaming.
  4. If you want to be one of the people employed at subsistence standard of living to gather wood, go right ahead.  This is your fantasy, not mine.
  5. If you think bio-fuel plants have zero emissions, you should listen to the odor complaints from the CWT plant in Carthage, MO.
And whatever you're smoking, I want some.

Henric

Engineer, your reasoning is sound. Where do you get the 20 % tank to wheels though? If ICE is 35%, then TtoW is going to be only a little less, like 30%, 5% lost in the transmission.
However, you should understand my position. Where I live there are no fossil fuel sources at all. But there are lots of forests and woody biomass stuff (and no, corn does not grow in this climate, it's too cold for that). I don't want to by fuel from the big boys across the border. BtL is very logical. The existing fleet gets liquids, future HEV's will need them too. Lower emmissions from the transport sector as they want. I am not going to wait until somebody gives me some kind of superbattery BEV which there is even no infrastructure to charge.
But of course I am not telling you big rich Americans not to develop batteries. You invented the automobile and polluted the world, now get something cleaner and better in place! ;)

Engineer-Poet
Where do you get the 20 % tank to wheels though?
From here, which states 14.9% but I decided to be charitable and call it 20%.  Note that this is fuel-to-resistance drag, and counts braking as a system loss.
If ICE is 35%, then TtoW is going to be only a little less, like 30%, 5% lost in the transmission.
That's the optimum efficiency.  Average is far less; cars creeping in traffic have very low engine efficiency near idle and large losses in torque converters.
Where I live there are no fossil fuel sources at all. But there are lots of forests and woody biomass stuff (and no, corn does not grow in this climate, it's too cold for that). I don't want to by fuel from the big boys across the border.
So don't.  There are many alternatives.
BtL is very logical.
Yet among all the alternatives, this is THE one you fix on.  Batteries are far more efficient, and let you use sources of energy which cannot be made into liquids.  Biomass-to-electric-to-wheels is more efficient than BtL.  Why BtL?

Even if you need to keep using ICEs for a while, you could convert biomass to charcoal (burning the off-gas to make electricity, or perhaps CHP) and then use the charcoal in gasogenes.  You would not incur the 50-70% losses in the BtL process.  What's the big advantage of BtL?  That you can sell it through a pump with an oil-company logo on it?

The existing fleet gets liquids, future HEV's will need them too.
The existing fleet has a lifespan of about 17 years; current US vehicles cover half their lifetime mileage in about 6 years.  PHEVs will need about 20-30% as much liquid fuel as today's vehicles, and the rest will be electric.  A PHEV with a gasogene for long trips could be nearly liquid-free.
I am not going to wait until somebody gives me some kind of superbattery BEV which there is even no infrastructure to charge.
You're painting the issue as all-or-nothing, with no grades in between.

sjc

I still like my solar car port. I can charge enough to run the car 50 miles from the sun. $20k for the port and $20k for the car and I replace the batteries after 5 years when they cost less.

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